1. Field of the Invention
The present invention relates to a linear guide apparatus, and more specifically to a linear guide apparatus including a fixed body, a movable body movable in a predetermined direction on the fixed body, and a retainer for rotatably supporting rolling bodies disposed between and in contact with the fixed body and the movable body. The linear guide apparatus can be used with a flat linear pulse motor, for instance.
2. Description of the Prior Art
FIG. 8 shows an example of prior-art linear guide apparatus used with a linear pulse motor, in which a retainer 63 for supporting rolling bodies such as balls or rollers is disposed between a fixed body 61 and a movable body 62. In the case of a linear pulse motor, a stator formed with magnetic pole teeth is fixed to the fixed body 61, and other magnetic pole teeth are formed in the movable body 62 so as to be opposed to the magnetic pole teeth of the stator, so that the movable body 62 can be moved in the direction that the magnetic pole teeth are arranged, on the basis of the magnetic field generated at the stator. The movement direction of the movable body 62 relative to the fixed body 61 is restricted because the balls (rolling bodies) 64 supported by the retainer 63 are fitted into and guided along V-shaped grooves 61a and 62a formed in the fixed body 61 and the movable body 62, respectively. When the movable body 62 moves in the arrow direction A, the balls 64 in contact with the movable body 62 rotate in the arrow direction B, so that the retainer 63 also moves relative to the fixed body 61 in the arrow direction A by the rotational movement of balls 64.
In the prior-art linear guide apparatus as described above, however, since slippage easily occurs between the movable body 62 and the rolling bodies 64 and between the rolling bodies 64 and the fixed body 61, an error is inevitably produced in the relative positional relationship among the fixed body 61, the retainer 63 and the movable body 62 when the movable body 62 starts to move or is braked, so that it is difficult to move the movable member 62 precisely. In addition, since the V-shaped grooves 61a and 62a are open at both the end thereof (i.e. no stopper members are provided), there exists a problem in that the rolling bodies 64 fall away from the ends of their respective V-shaped grooves 61a and 62a due to accumulated error and therefore the apparatus may be damaged.